1. Field of the Invention
The present invention relates in general to a medical article anchoring system. In one mode, the present invention involves a catheterization system that interconnects an indwelling catheter with medical tubing and securely anchors the interconnection to a patient""s skin.
2. Description of the Related Art
Medical treatment of patients commonly involves the use of percutaneously inserted catheters to deliver fluids directly into the bloodstream, a specific organ or an internal location within the patient, or to monitor vital functions of the patient. For instance, short, peripherally-inserted, intra-arteriovenous catheters are commonly used to direct fluids and/or medications directly into the bloodstream of the patient.
The fluid (e.g., parenteral liquid, medication, etc.) typically drains from a container positioned above the patient to feed under gravity or is delivered via an infusion pump. The fluid flows through tubing and thence into the indwelling catheter. The catheter and the fluid tubing are commonly removably attached to each other by a conventional luer lock connection.
A luer lock connection generally includes a male luer connector with a tapered conical portion that is adapted to fit into a correspondingly shaped receptacle of a female luer connector (i.e., a hub). A spin nut is commonly disposed on the male luer connector and is rotatable relative to the tapered conical portion. The spin nut includes internal threads that are adapted to engage external threads on the female luer connector to lock together the luer connectors. When properly engaged, the conical portion fits tightly within the receptacle to produce a sealed interconnection.
A healthcare provider can experience difficulty at times breaking the seal between the engaged conical portion and the hub of the luer lock connectors when disconnecting the male luer connector from the female luer connector. In order to aid such disconnection, some luer lock connectors include spin nuts that can slide axially between a distal position, in which the spin nut can freely rotate relative to the coupled luer connectors, and a proximal position, in which the spin nut and male luer connector are rotationally locked. The rotational lock is provided to assist in breaking the sealed coupling between the corresponding surfaces of the conical portion and the hub of the interengaged luer lock connectors.
An example of this type of luer lock connector is described in U.S. Pat. No. 5,620,427, which issued Apr. 15, 1997 to Werschmidt et al. (referred to below as xe2x80x9cthe ""427 patentxe2x80x9d). The disclosed connector provides tapered engagement surfaces providing a gradual frictional engagement when tightening the spin nut to minimize inadvertent reverse rotation and loosening of the spin nut. Also, a plurality of axially extending splines for engagement with a plurality of inwardly, radially directed ribs on the spin nut allow positive rotationally locking of the spin nut and the male luer connector when the spin nut is in a proximal position. The spin nut, when locked with the male luer connector, provides greater leverage to produce more torque on the male luer connector to break the sealed coupling.
In common practice, a healthcare provider uses adhesive, foam or surgical tape to maintain the luer lock connector, and thus the catheter, in place on the skin of the patient. The healthcare provider wraps a thin piece of tape around the luer lock connector and then forms a xe2x80x9cchevronxe2x80x9d with the tape, placing the ends next to the sides of the indwelling catheter. The healthcare provider then places one piece of tape across and over the connector, forms a loop in the tubing, places another piece of tape across the tubing loop, and places yet an additional piece of tape over the catheter hub and the tubing section that has been looped around and extends next to the indwelling catheter. This step forms a safety loop in the tubing so that any tension applied to the tubing does not directly pass to the catheter cannula, but rather is absorbed by the slack of the safety loop. Subsequently, the healthcare provider typically covers the insertion site and the indwelling catheter with a transparent dressing.
The entire taping and dressing procedure takes several minutes of the healthcare provider""s valuable time. In addition, the catheterization process often requires relatively frequent disconnection between the catheter and the fluid supply tube, as well as dressing changes. For instance, intravenous catheterization is frequently maintained for several days, depending upon the condition of the patient. The tubing is generally replaced every 48 to 72 hours in order to maintain the sterility of the fluid and the free-flow of the fluid through the tubing. A healthcare provider thus must frequently change the tubing and retape the connection. The healthcare provider also must frequently clean the insertion site about the indwelling catheter and change the dressings. Moreover, the tape, which secures the catheter to the skin of the patient, often covers the cannula insertion point. The healthcare provider must remove the tape to inspect the insertion point for inflammation or infection, and must then repeat the above-described taping procedure.
The healthcare provider thus uses a great deal of valuable time applying, removing and reapplying tape. The frequent application and removal of the tape also commonly excoriates the patient""s skin about the insertion site.
In addition, the traditional method of intravenous catheter securementxe2x80x94surgical tape and transparent dressings alonexe2x80x94have not always prevented catheter migration and/or dislodgment. Taped intravenous catheters are also easily pulled out during a xe2x80x9croutinexe2x80x9d dressing change, especially by inexperienced healthcare providers. And if the catheter migrates too far or dislodgment occurs, the healthcare provider must replace the catheter, thus exacerbating the time and expense required to maintain the intravenous feed. Such catheter re-starts also poses the risk of needle stick to the healthcare provider.
Prior securement methods have not served the patient as well. Surgical tape or foam strips are uncomfortable. Many patients also do not rest comfortably and worry about catheter dislodgment when they move, when only tape and a dressing secure the catheter in place.
Several additional drawbacks result from the use of tape to stabilize the catheter. One is contamination. Healthcare providers often tear off small strips of tape and place them on the hand rail on the patient""s bed. Clostridium and other bacteria commonly exist on these surfaces and can be transferred to the patient""s skin in the proximity of the insertion site.
In addition, tape securement requires the healthcare provider to handle the tape while wearing protective latex gloves. Tearing adhesive tape tends to produce microscopic and/or visible holes in the gloves and thus destroys glove barrier protection.
A number of catheter securement systems have been developed to obviate the need for frequent application of tape to secure a catheter to a patient. One such securement system is disclosed in U.S. Pat. No. 5,456,671, issued Dec. 10, 1995, to Steven F. Bierman, M.D. (hereinafter referred to as xe2x80x9cthe ""671 patentxe2x80x9d). The preferred form of the securement system disclosed in this patent involves a retainer having a plurality of lateral slots. Each slot has a similar size and is designed to receive a collar of an associated catheter connector or adaptor. The cooperating structure of the connector and the retainer, i.e., the slots and the collar, arrests longitudinal movement of the connector through the retainer, and permits quick insertion of the connector into the retainer. The healthcare provider need not worry about the rotational orientation of the connector above the retainer and only need to align coarsely the collar of the connector above the series of slots before pushing the connector into the retainer.
The retainer, which is disclosed in the ""671 patent, does not work as well with the connector disclosed in the ""427 patent. As noted above, the connector disclosed in the ""427 patent has a plurality of axially extending splines that are spaced around a portion of the circumference of the connector""s tubular body. At least one of these splines has a longer length than that of at least one of the other splines. Because the slots in the illustrated form of the retainer disclosed in the ""671 patent all have the same size, the rotational orientation of the connector becomes important before the connector is inserted into the retainer. Insertion of the connector into the retainer thus requires more effort and care, thereby decreasing the ease of using the securement system disclosed in the ""671 patent.
In accordance with one aspect of the present invention, an anchoring system provides releasable securement of a medical article (i.e., a catheter) to the patient. The releasable engagement is achieved by cooperation between a retainer, a connector or a section of the medical article, and an anchor pad. This cooperation allows the medical article to be disconnected from the anchoring system, and from the patient, for any of a variety of known purposes. For instance, a healthcare provider may want to remove the medical article from the anchoring system to ease disconnection of the medical article from the patient or to clean the patient. The disengagement of the medical article from the anchoring system, however, can be accomplished without removing the anchoring system from the patient.
The present anchoring system also arrests movement of the medical article and/or the connector with respect to the anchoring system. Transverse, lateral and longitudinal (i.e., axial) movement is generally inhibited by the holding effect provided by the retainer. That is, the retainer generally surrounds the connector and/or section of the medical article while recesses within the retainer capture projections on the connector or the medical article.
Sturdy anchoring of the medical article thus is achieved without the use of surgical tape. Additionally, the anchoring system is attached to the patient only once for most intravenous courses. Although the fluid supply tubing may be replaced every 24 to 48 hours for intravenous catheterization, the components of the present anchoring system remains in place through multiple dressing and supply tubing changes. Thus, surgical tape need not be applied and removed from the patients"" skin on multiple occasions.
In one mode, the anchoring system is configured to securely anchor a luer lock connector of the type that includes an elongated tubular body with at least first and second axially extending splines. The second axially extending spline has a longer longitudinal length than that of the first axially extending spline, and the tubular body extends in a longitudinal direction from a proximal end to a distal end. The connector disclosed in U.S. Pat. No. 5,620,427 is an example of this type of lure lock connector.
The anchoring system comprises a retainer and an anchor pad. The retainer is affixed to one side of the anchor pad, and the other side of the anchor pad includes an adhesive layer that is adapted to secure the anchor pad and the retainer to the skin of the patient.
The retainer includes a body having first and second end portions and an intermediate portion. The intermediate portion includes a pair of flexible walls. A channel extends through at least the first and second end portions and through the intermediate portion of the body between the flexible walls. The flexible walls are deflectable away from a central axis of the channel. The first end portion defines a first abutment surface that lies generally normal to the central axis of the channel, and the second end portion defines a second abutment surface that lies generally normal to the central axis of the channel. The second abutment surface generally opposes the first abutment surface. The first and second abutment surfaces are spaced from each other by a distance greater than the longitudinal length of the second spline of the tubular body. At least one of the flexible walls includes third and forth abutment surfaces that lie generally normal to the central axis of the channel and that generally oppose each other. The third and fourth abutment surfaces are spaced apart from each other by a distance that generally corresponds to the longitudinal length of the first spline of the tubular body.
In a preferred form, the distance between the first and second abutment surfaces generally corresponds to a longitudinal length measured between the proximal end of the connector tubular body and a distal end of the second spline. The first end portion also includes a fifth abutment surface positioned distal of the first abutment surface. The fifth abutment surface is distanced from the second abutment surface by a distance substantially equal to the longitudinal length of the second spline. Additionally, the other flexible wall also includes abutment surfaces that correspond to the third and fourth abutment surfaces.
The retainer arrests longitudinal movement of the connector with respect to the anchoring system in at least a distal direction, at least in part by retaining one or more of the splines. For example, with respect to a retainer configured in accordance the preferred mode, the second spline is captured between the second and fifth abutment surfaces when the connector is inserted into the retainer with the second spline oriented downwardly (i.e., facing the retainer channel) or to one side. With the connector so situated, the second spline causes the corresponding flexible wall to deflect laterally outward and occupies the space between the second and fifth abutment surfaces. When the retainer is inserted into the retainer with the second spline oriented upwardly (i.e., facing away from the retainer channel) or downward, the first spline is captured between the abutment surfaces on one of the flexible walls, i.e., between the third and forth abutment surfaces. Accordingly, at least one spline is captured between a corresponding pair of abutment surfaces regardless of the orientation of the longer second spline (e.g., oriented upwardly, downwardly or to one side) when the connector body is inserted into the retainer. The corresponding pair of abutment surfaces thus arrest longitudinal movement of the connector in both the proximal and distal directions along the longitudinal axis.
Additionally, the first abutment surface lies just proximal of the proximal end of the connector body when the retainer receives the connector, no matter how the second spline is situated. The first abutment surface thus also inhibit longitudinal movement of the connector in the proximal direction. For this reason, it is understood that one or more of the distal facing abutment surfaces (i.e., the third and fifth abutment surfaces) can be omitted from the retainer. It also is understood that the first abutment surface can be omitted from the retainer where the retainer includes one or more of the other distal facing abutment surfaces (e.g., the third abutment surface and/or the fifth abutment surface) to arrest movement in the proximal direction. Thus, in the preferred mode of the retainer, at least two of these distal facing abutment surfaces (i.e., the first, third and fifth abutment surfaces) redundantly inhibit longitudinal movement of the connector in the proximal direction at all times when the connector body is inserted into the retainer channel.
The anchoring system thus is designed for a healthcare provider to quickly insert the connector into the retainer, without requiring precise alignment or positioning of the connector on the anchoring system. That is, the healthcare provider need not be concerned with the rotational orientation of the catheter body before inserting it into the retainer as the retainer can properly receive the connector with the longer second spline lying at any position (e.g., upward, downward, or to one side relative to the retainer channel).
The retainer also can be configured to interact with a connector that has splines with staggered positions along the length of the connector body. For example, a connector can have splines of the same length, but a distal end of one of the splines lies closer to a distal end of the connector than a distal end of another spline. The present retainer can be configured to hold such a connector. The ability of one retainer wall section, which includes at least one abutment surface, to deflect relative to the adjacent retainer wall sections, which each also include at least one abutment surface, enables the retainer to accommodate a connector having splines with distal end positions differing along the length of the connector body, regardless of whether such differing distal end positions occur because of differing lengths, a staggered arrangement, or a combination of the two.
In addition, the retainer can be configured to interact with a connector having splines of equal lengths and at the same axial location along the connector""s length. In such case, the retainer need not include all five abutment surfaces (e.g., it could include only two or three abutment surfaces).
In a variation, a catheter hub or body can include splines or other projections, and the retainer can be configured to receive a section of the catheter (e.g., the catheter hub) and to capture one or more of the corresponding splines or projections to arrest axial movement of the catheter.
Another aspect of the present invention involves an anchoring system for a medical article. The anchoring system comprises an anchor pad, which has upper and lower sides, and a retainer. The retainer is disposed on the upper side of the anchor pad. The lower side of the anchor pad includes an adhesive surface to secure the retainer to the skin of a patient. The anchor pad also includes at least one elongated extension with an adhesive undersurface. The extension is adapted to be rolled upon itself around a portion of the medical article. In this manner, the extension can be used to secure a section of the medical article to the anchor pad. The secured section can thus, for example, form a safety loop along the length of the medical article.
In accordance with an additional aspect of the present invention, a catheterization system comprises a catheter connector, a retainer and an anchor pad. The connector includes an elongated tubular body that extends in a longitudinal direction from a proximal end to a distal end and has at least first and second axially extending splines disposed on and extending radially from the tubular body. The second axially extending spline has a longer longitudinal length than that of the first axially extending spline. In one mode, the catheter connector is located at the proximal end of the catheter and, in another mode, the catheter connector is located at a distal end of a fluid tube (e.g., a fluid delivery or drainage tube) which is to be coupled to a catheter.
The retainer includes a body and channel that extends longitudinally through at least a portion of the body. The body defines at least first, second, third and fourth abutment surfaces positioned along the channel and extending laterally therefrom so as to lie generally normal to an axis of the channel. The second and third abutment surfaces are arranged between the first and fourth abutment surfaces in the longitudinal direction. The first and fourth abutment surfaces are spaced apart by a distance that is at least a long as the longitudinal length of the second spline, and the second and third abutment surfaces are spaced apart by a distance that is substantially equal to the longitudinal length of the first spline.
The anchor pad includes upper and lower sides. The retainer is disposed on the upper side of the anchor pad, and the lower side of the anchor pad including an adhesive surface to secure the retainer to the skin of a patient.
Another aspect of the present invention involves an anchoring system for securely anchoring a medical article to a patient. The anchoring system comprises a retainer including a body and a channel that extends longitudinally through at least a portion of the body. The body defines at least first, second and third abutment surfaces positioned along the channel. The first, second and third abutment surfaces extend generally laterally from the channel. The second abutment surface is laterally moveable relative to one of the first and third abutment surfaces and is disposed between the first and third abutment surfaces.
A further aspect of the present invention involves an anchoring system for securely anchoring to a patient a luer lock connector of the type having an elongated tubular body that extends in a longitudinal direction from a proximal end to a distal end, and that includes at least first and second axially extending splines. The anchoring system comprises a retainer including a body having first and second end portions and an intermediate portion between the first and second end portions. The intermediate portion includes a pair of flexible walls. Each wall is deflectable relative to the first and second end portions. A channel extends through at least the first and second end portions and through the intermediate portion of the body between the flexible walls. The flexible walls are deflectable away from a central axis of the channel. The first end portion defines a first abutment surface that lies generally normal to the central axis of the channel, and the second end portion defines a second abutment surface that lies generally normal to the central axis of the channel and that generally opposes the first abutment surface. At least one of the flexible walls includes a third abutment surface that lie generally normal to the central axis of the channel at a location between the first and second abutment surfaces.
In a preferred mode, the anchoring system also includes an anchor pad. The retainer is affixed to one side of the anchor pad, and the other side of the anchor pad includes an adhesive layer adapted to secure the anchor pad and the retainer to the skin of the patient. The retainer also can be secured to the patient in other ways, for example, by suturing, although this mode of securement is less preferred.
In accordance with a preferred method of securing a luer lock connector on a retainer of an anchoring system, a luer lock connector is provided that includes at least first and second splines with differing end points (i.e., differing points at which the splines end) along the length of the connector. The lure lock connector is inserted into a channel of a retainer without regard to the orientation of the splines so that the splines may be in any of a plurality of positions with respect to the retainer when inserted. The splines are in a first position of the plurality of positions with the first spline facing laterally, and are in a second position of the plurality of positions with the first spline rotated from the first position such that the second spline faces laterally. The method further involves longitudinally restraining (a) the first spline between a first pair of abutment surfaces of the retainer if the splines are in the first position, or (b) the second spline between a second pair of abutment surfaces of the retainer if the splines are in the second position. At least one abutment surface of the second pair of abutment surfaces is different from one of the abutment surfaces of the first pair of abutment surfaces.
For purpose of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. Of course, it is to be understood that not necessarily all such objects or advantages be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages taught or suggested herein. Additionally, further aspects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiment that follows.